Electrical connectors are used to interconnect signal transmission lines to printed circuit boards, other electronic devices or to other complementary connectors. The transmission lines transmit signals through a plurality of conductors which, preferably, are physically separated and electromagnetically isolated along their length.
In the electronics industry, particularly the computer industry, the predominant system embodies a plurality of plug-in type connectors in mating engagement with receptacle connectors on the computer, its main printed circuit board or other electronic devices. The transmission lines typically include coaxial electrical cables, either in round or flat form, and round cables are presently being used predominantly in relatively high frequency applications between various system components.
Classical coaxial designs derive their characteristic impedance from the geometrical relationship between the inner signal conductors and the outer shield member and the intervening dielectric constant. For a given impedance, signal conductor size and dielectric material, an overall outside dimension is defined. In order to increase signal density and reduce the overall outside dimensions of a transmission line connector system, alternate geometries and/or dielectric materials are required.
For data processing purposes, cables usually utilize twisted pairs of conductors to achieve the necessary characteristics, particularly impedance control and cross talk control. Coaxial cables are frequently used in singular, isolated, conductor configurations in high frequency applications, such as to a high-speed, high-resolution video monitor for the transmission of red, green and blue video signals. Most often, the lower speed data transmission lines are separated from the high speed signal transmission lines. Consequently, different electrical connectors are often used for the lower speed data transmission lines than for the high speed signal lines. This adds to the problem of requiring multiple connectors in ever-increasing miniaturized and high density applications.
In order to solve such problems as identified immediately above, an improved electrical connector was designed as shown in U.S. Pat. No. 5,102,353 to Brunker et al, dated Apr. 7, 1992 and assigned to the assignee of this invention. That patent shows an electrical connector which terminates both high speed signal transmission lines and the slower data transmission lines in a unique manner providing a common ground system for all of the high frequency conductors to reduce the number of interconnections predominant in the prior art and to increase signal contact density while maintaining a desired impedance level.
The present invention is directed to further improvements in electrical connectors of the character described above and of the type shown in the U.S. Pat. No. 5,102,353 patent. In particular, this invention is directed to reducing capacitive coupling and crosstalk between the arrays of high speed signal terminals and lower speed data terminals of the high and low speed transmission lines.